Originally Posted by RonS
They cannot make you get rid of them. Some excerpts from various sites on the subject: Ex post facto laws are expressly forbidden by the United States Constitution in Article 1, Section 9, Clause 3 and further sections apply to the states as well. Ex post facto laws (Latin for "from after the action" or "after the fact"), also called a retroactive law, is a law that retroactively changes the legal consequences (or status) of actions that were committed, or relationships that existed, before the enactment of the law. If your state government tries to make a law and force you to get rid of your mags after you already own them then they are in direct violation of the Constitution.
NYS just passed a law that does that. Pre-ban mags over 10 rounds were legal, but now have to be out of the state before the end of the year.
10 round mags stay legal, but cannot be loaded with more than 7 rounds, which is probably one of the most idiotic things I've ever heard of. "But officer, I must have miscounted". "Sorry, 8 rounds in there, gonna' have to take you in".